New 351w running rich and bad idle
#16
03-25-2015, 08:50 AM
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Thanks for the replies guys.
The o2 sensor is brand new, replaced it after the head gasket issues were fixed. I also unplugged the computer after the egr valve.
I did consider the exhaust leaking. The o2 sensor is located right after the connection from the header and exhaust system. The headers use what I would describe as a "ball and socket" type of connection. It doesn't use any type of a gasket, just three bolts to clamp the two sides together. I could see it pulling air into the exhaust if its not completely sealed. I'm going to look into welding another bung ahead of that connection in the collector. Unless you have any suggestions on sealing the connection up in some way.
Thanks
The o2 sensor is brand new, replaced it after the head gasket issues were fixed. I also unplugged the computer after the egr valve.
I did consider the exhaust leaking. The o2 sensor is located right after the connection from the header and exhaust system. The headers use what I would describe as a "ball and socket" type of connection. It doesn't use any type of a gasket, just three bolts to clamp the two sides together. I could see it pulling air into the exhaust if its not completely sealed. I'm going to look into welding another bung ahead of that connection in the collector. Unless you have any suggestions on sealing the connection up in some way.
Thanks
#18
03-25-2015, 02:21 PM
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Location: Minneapolis, MN
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Improvement,
I swapped out the computer with one for a 1990 (oddly they both had the exact same codes and part numbers marked on them, but the shape of the case was completely different). Now it is definitely running better but some of the idle issues are still there, just not as bad. It seems to be running much less rich as well.
Now the only codes i'm pulling are-
KOEO-34, 85
CM-34
KOER-12
Just to make sure i'm not just missing the plug, does the canister purge solenoid plug go into the engine wiring harness or the body? I thought that it separated from the harness around the TPS or IAC valve.
Also,
I just got a very very good book on ford fuel injection and it sounds like the code 34 could be the idle culprit. The way i'm understanding it, the code 34 is saying that there is not enough resistance at the EVP when it is closed allowing too much voltage to read back.
But I am getting some conflicting information. The fuel injection book says that the resistance should go from 5,500 ohms closed to 100 ohms open. My Haynes manual says it should be slightly less than 5,000 ohms (but no greater than) closed to slightly greater than (but no less than) 100 ohms.
I tested the one I just installed and it was 4,600 to 350 ohms. I put more faith in the EFI book than haynes so I picked up another. I haven't even run the truck with it yet because its reading 4200 to 370 ohms. Even going off Haynes, that seems like much more than slightly less than 5,000 ohms and slightly more than 100 ohms. Did I get two bad sensors or are these readings good?
Thank you.
I swapped out the computer with one for a 1990 (oddly they both had the exact same codes and part numbers marked on them, but the shape of the case was completely different). Now it is definitely running better but some of the idle issues are still there, just not as bad. It seems to be running much less rich as well.
Now the only codes i'm pulling are-
KOEO-34, 85
CM-34
KOER-12
Just to make sure i'm not just missing the plug, does the canister purge solenoid plug go into the engine wiring harness or the body? I thought that it separated from the harness around the TPS or IAC valve.
Also,
I just got a very very good book on ford fuel injection and it sounds like the code 34 could be the idle culprit. The way i'm understanding it, the code 34 is saying that there is not enough resistance at the EVP when it is closed allowing too much voltage to read back.
But I am getting some conflicting information. The fuel injection book says that the resistance should go from 5,500 ohms closed to 100 ohms open. My Haynes manual says it should be slightly less than 5,000 ohms (but no greater than) closed to slightly greater than (but no less than) 100 ohms.
I tested the one I just installed and it was 4,600 to 350 ohms. I put more faith in the EFI book than haynes so I picked up another. I haven't even run the truck with it yet because its reading 4200 to 370 ohms. Even going off Haynes, that seems like much more than slightly less than 5,000 ohms and slightly more than 100 ohms. Did I get two bad sensors or are these readings good?
Thank you.
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